"Gosh" you might say, "that's one weird looking jellyfish". Well, you'd be partly right. Certainly it looks rather odd but it isn't a jellyfish, it isn't even one animal. The Portuguese Man o' War is in fact a whole colony of four different kinds of organism, each adapted to perform a specific function for the benefit of the whole.
They are all either a kind of polyp, which are like really small sea anemones, or medusae, similar to tiny jellyfish, but here they are all connected to each other and are unable to survive on their own. Such is the way of the siphonophores, an order of colonial creatures related to... can you believe it? Sea anemones and jellyfish. In case you were wondering, the whole thing develops from one egg that sprouts all the other parts, rather than loads of little polyps undertaking an epic journey of self discovery in search of their People.